The increase in circuit density and operating frequency of integrated circuits and multi-chip modules utilized in present day computer systems has resulted in an exponential increase in the power dissipated by those components. For example, just a few years ago the maximum power generated by a typical complementary metal oxide semiconductor (CMOS) central processor unit (CPU) utilized within a personal computer was in the neighborhood of two watts. Currently, the Intel Corporation Pentium processor dissipates an estimated sixteen watts, and the next generation Intel Corporation processor is estimated to generate near thirty watts. Cooling arrangements must be provided to prevent damage to these integrated circuits from the high temperatures generated by the devices. Traditional cooling techniques such as radiation or convection into the atmosphere are no longer adequate to provide the heat removal required for these high power integrated circuits.
In addition to cooling to prevent damage resulting from overheating, it is known that a CMOS circuit will operate at higher clock speeds as the circuit temperature is lowered. In some cases the processor frequency of CMOS processor has been improved to near 300% through the cooling of the processor die to a temperature of approximately --200.degree. C. Many methods for sub-cooling processors and other computer components are known. One such cooling system comprises a plurality of hollow cold plates which are attached to the processors, modules or other components to be cooled. A liquid coolant is circulated from a refrigeration unit through connecting conduits to the cold heads to effectuate cooling of the attached components. Other known cooling methods include immersion of the CPU module in a coolant such as liquid nitrogen, or interfacing the CPU module with a Peltier TEC (thermal electric cooling) device.
The requirement for cooling of high power components presents additional considerations and difficulties in the design, construction and operation of a computer system. For example, an immersion or liquid cooling system as described above requires thick insulation of conduits, cold plates and other cooling system components, taking up valuable cabinet space. Unavoidable heat leakage requires that the cooling system be oversized to allow for losses. An additional concern is that condensation may form on the cold elements of the cooling system, such as the conduits and cold heads. This condensation can damage electrical components within the computer system.